Bring the broth to the boil.
Drop in the rice cakes and cook over medium-high heat, covered, for about seven minutes.
Taste the broth. Add salt and pepper, if needed (the rice cakes would have soaked up some of the saltiness and the broth might taste bland at this point).
Throw in the spinach, pushing the leaves down into the broth. Lower the heat, cover and cook for another two to three minutes.
Ladle into bowls. Sprinkle with toasted garlic bits and cilantro.
Squeeze a lime or lemon wedge over the soup before digging in.